Solid phase extraction separation method and kit for separating actinides individually

Abstract

The invention relates to a solid-phase extraction separation method and a kit for respectively separating actinide elements. The actinide element is U, Np and / or Pu, and at least one element X selected from Am or Cm. The method comprises the following steps: (1) a test solution containing the actinide elements flows through a cascade column formed by sequentially connecting a separation column 1 and a separation column 2 in series from one side of the separation column 1, the separation column 1 is filled with resin 1, the resin 1 comprises porous base resin 1 and a complexing agent 1 which is loaded on the porous base resin 1 and is used for complexing with U, Np and / or Pu, the separation column 2 is filled with resin 2, and the resin 2 is used for separating the actinide elements; the resin 2 comprises porous base resin 2 and a complexing agent 2 which is loaded on the porous base resin 2 and is used for complexing with the element X; and (2) eluting the separation column 1 by using an Np eluent containing AHA and nitric acid, a Pu eluent containing oxalic acid and ascorbic acid, and / or a U eluent containing ammonium carbonate, and eluting the separation column 2 by using an element X eluent containing AHA and hydrochloric acid. The kit comprises the cascade column and the eluent.

Description

TECHNICAL FIELD

[0001] The present application relates to a solid phase extraction separation method and kit for separating U (uranium), Np (neptunium) and / or Pu (plutonium) from at least one element X selected from Am (americium) or Cm (curium) respectively, belonging to the technical field of radionuclide separation. BACKGROUND

[0002] In the field of radioassay, especially in the field of radioassay related to nuclear activities using uranium as fuel, actinides U, Np, Pu, Am / Cm are often the focus of attention. The analysis of these actinides usually adopts spectral measurement, radioactivity measurement or mass spectrometry. Regardless of which measurement method is used, element separation is often an essential link for accurate quantification. (Here and hereinafter, "Am / Cm" means at least one selected from Am and Cm, i.e. Am and Cm are not separated, and the radioactivity ratio of Am and Cm can be obtained by alpha energy spectrum measurement.)

[0003] The separation of actinides U, Np, Pu, Am / Cm, etc. often uses liquid-liquid extraction technology and solid phase extraction technology. Since the latter has the advantages of less organic waste liquid, no emulsification problem, and easier automation than the former, the method of separating actinides by solid phase extraction technology is increasingly favored by researchers.

[0004] There are many reports in the literature on separating actinides using commercial resins such as TRU, TEVA, UTEVA, DGA, TK200, etc. However, the target elements are mostly single, and there are few reports on techniques that include U, Np, Pu, Am / Cm in the target elements. Generally, the more elements to be separated, the greater the technical difficulty will be.

[0005] For example, Snow et al. used one TEVA column and two anion exchange columns to separate U / Am, Np, and Pu, in which U and Am were not separated, and the process included precipitation and evaporation operations between the three columns, which was complicated (Journal of environmental radioactivity, 2017, 172: 89-95). Engel et al. used three TEVA columns and one DGA column to separate Np, Pu, and Am from a U matrix, and the sample solution needed to be re-dosed before entering the third TEVA column, resulting in a discontinuous separation process that was not conducive to automation of the column separation process, and the recovery rate of Np was only 62% (Journal of radioanalytical and nuclear chemistry, 2023, 332: 3205-3214). Xing et al. used one TK200 column and one DGA column to separate Np / Pu and Am / Cm, in which Np and Pu were not separated, and U analysis was not considered (Analytical chemistry, 2023, 95: 3647-3655).

[0006] Therefore, there is a need in the art for a separation method that can simultaneously separate multiple actinides, such as U, Np, and / or Pu from Am / Cm, and can be operated continuously and easily automated. SUMMARY

[0007] <Problems to be solved by the invention>

[0008] In view of the above, the present inventors have conducted in-depth research on mixed samples containing U, Np, and / or Pu and Am / Cm, and found that the main difficulty in separating these elements individually lies in how to achieve the following three points simultaneously: (1) Np and Pu can be separated, and the separation of Np and Pu cannot affect the recovery rate of U, Am / Cm; (2) the salt content in the respective eluents of each element after column separation is as low as possible, so that the sample can be concentrated and / or an alpha surface source (for alpha energy spectrum measurement) can be prepared if necessary, and the recovery rate of each element from its respective eluent can even be higher than 95%; (3) the column separation process should be continuous, and cannot be re-dosed, nor can it have precipitation, evaporation, or other operations, in order to automate the column separation process.

[0009] Therefore, the present application aims to provide a solid phase extraction method capable of separating each of actinide elements (U, Np, and / or Pu, and Am and / or Cm) simultaneously, which can achieve rapid separation of various actinide elements (even rapid separation of U, Np, Pu, Am / Cm) in an easy manner, has a good separation effect, has a recovery rate of each element in each eluent of more than 95%, has a very low salt content in each eluent, can be continuously operated throughout the column separation process, has a very simple operation process, is easy to automate, has a wide range of applications, and is suitable for large-scale industrial production.

[0010] The present application also aims to provide a solid phase extraction kit capable of separating each of actinide elements (U, Np, and / or Pu, and Am and / or Cm) simultaneously, which can be used to achieve rapid separation of various actinide elements (even rapid separation of U, Np, Pu, Am / Cm) in an easy manner, has a good separation effect, has a recovery rate of each element in each eluent of more than 95%, has a very low salt content in each eluent, can be continuously operated throughout the column separation process, has a very simple operation process, is easy to automate, has a wide range of applications, and is suitable for large-scale industrial production.

[0011] <Means for solving the problem>

[0012] Through in-depth research by the inventors, it has been found that the following embodiments can be used to solve the above technical problems.

[0013] [1]. A solid phase extraction separation method for separating each of actinide elements, the actinide elements being U, Np, and / or Pu and an element X, the element X being at least one selected from Am or Cm, the method comprising:

[0014] (1) passing a test solution containing the actinide elements through a cascade column composed of a separation column 1 and a separation column 2 connected in series, and the test solution entering the cascade column from the separation column 1 side of the cascade column,

[0015] the separation column 1 being packed with a resin 1 including a porous base resin 1 and a complexing agent 1 supported on the porous base resin 1,

[0016] the complexing agent 1 being represented by the following formula (1):

[0017] (1)

[0018] In formula (1), each R1 is independently an alkyl group;

[0019] the separation column 2 being packed with a resin 2 including a porous base resin 2 and a complexing agent 2 supported on the porous base resin 2,

[0020] The complexing agent 2 is represented by the following formula (2):

[0021] (2)

[0022] In formula (2), R2is each independently an alkyl group;

[0023] (2) eluting the separation column 1 with an Np eluent, collecting an eluate containing Np that flows out, eluting the separation column 1 with a Pu eluent, collecting an eluate containing Pu that flows out, and / or eluting the separation column 1 with a U eluent, collecting an eluate containing U that flows out; and eluting the separation column 2 with an element X eluent, collecting an eluate containing element X that flows out;

[0024] The Np eluent is a mixed solution containing acethydroxamic acid (AHA) and nitric acid;

[0025] The Pu eluent is a mixed solution containing oxalic acid and ascorbic acid;

[0026] The U eluent is a solution containing ammonium carbonate;

[0027] The element X eluent is a mixed solution containing acethydroxamic acid (AHA) and hydrochloric acid.

[0028] [2] The solid phase extraction separation method according to [1], wherein, in the test solution, U is in a +6 valence, Np is in a +6 valence, Pu is in a +4 valence, and element X is in a +3 valence.

[0029] [3] The solid phase extraction separation method according to [2], wherein the test solution is obtained by adding nitric acid and ammonium vanadate to a liquid to be treated containing the actinide element to perform acidity adjustment and oxidation pretreatment.

[0030] [4] The solid phase extraction separation method according to [1], wherein, in formula (1), R1is each independently a C4-12 straight-chain or branched alkyl group; and / or

[0031] In formula (2), R2is each independently a C4-20 straight-chain or branched alkyl group.

[0032] [5] The solid phase extraction separation method according to [1], wherein the porous base resin 1 and the porous base resin 2 are each independently at least one selected from the group consisting of (meth)acrylate porous resins and styrene porous resins; and / or

[0033] The loading amount of the complexing agent 1 in the resin 1 is 5-50 mass%; and / or

[0034] The loading amount of the complexing agent 2 in the resin 2 is 5 to 50 mass%.

[0035] [6]. The solid phase extraction separation method according to [1], wherein the separation column 1 is obtained by packing the resin 1 in a chromatographic column, and / or

[0036] The separation column 2 is obtained by packing the resin 2 in a chromatographic column.

[0037] [7]. The solid phase extraction separation method according to [1], wherein in the mixed solution containing acethydroxamic acid (AHA) and nitric acid, the concentration of acethydroxamic acid (AHA) is 0.05 to 1 mol / L, and the concentration of nitric acid is 0.1 to 4 mol / L; and / or

[0038] In the mixed solution containing oxalic acid and ascorbic acid, the concentration of oxalic acid is 0.05 to 1.0 mol / L, and the concentration of ascorbic acid is 0.02 to 0.8 mol / L; and / or

[0039] In the solution containing ammonium carbonate, the concentration of ammonium carbonate is 0.05 to 1.5 mol / L; and / or

[0040] In the mixed solution containing acethydroxamic acid (AHA) and hydrochloric acid, the concentration of acethydroxamic acid (AHA) is 0.01 to 1 mol / L, and the concentration of hydrochloric acid is 0.01 to 0.5 mol / L.

[0041] [8]. The solid phase extraction separation method according to [1], wherein the flow rate of each of the test solution and the eluents is 0.05 to 5 mL / min.

[0042] [9]. The solid phase extraction separation method according to [1], wherein in step (1), after the test solution is passed through the tandem column, a carrier solution not containing U, Np, Pu, and the element X is passed through the tandem column.

[0043]

[10] . A kit for solid phase extraction for separating each of actinide elements, the actinide elements being U, Np, and / or Pu, and the element X being at least one selected from Am or Cm, the kit comprising: a tandem column composed of a separation column 1 and a separation column 2 connected in series, and eluents for eluting the tandem column,

[0044] The tandem column has an inlet for injecting a test solution on the side of the separation column 1,

[0045] The eluents are an Np eluent for eluting the separation column 1, a Pu eluent for eluting the separation column 1, and / or a U eluent for eluting the separation column 1, and an element X eluent for eluting the separation column 2;

[0046] The separation column 1 is packed with resin 1, which includes a porous base resin 1 and a complexing agent 1 loaded on the porous base resin 1,

[0047] The complexing agent 1 is represented by the following formula (1):

[0048] (1)

[0049] In formula (1), R1 is independently an alkyl group;

[0050] The separation column 2 is packed with resin 2, which includes a porous base resin 2 and a complexing agent 2 loaded on the porous base resin 2,

[0051] The complexing agent 2 is represented by the following formula (2):

[0052] (2)

[0053] In formula (2), R2 is independently an alkyl group;

[0054] The Np eluent is a mixed solution containing acethydroxamic acid (AHA) and nitric acid;

[0055] The Pu eluent is a mixed solution containing oxalic acid and ascorbic acid;

[0056] The U eluent is a solution containing ammonium carbonate;

[0057] The element X eluent is a mixed solution containing acethydroxamic acid (AHA) and hydrochloric acid.

[0058] <Effects of the Invention>

[0059] In the present application, by making the test solution containing the elements to be separated sequentially pass through the separation column 1 and the separation column 2 respectively packed with specific porous resins, and eluting the separation column 1 and the separation column 2 with various eluents of specific components, U, Np and / or Pu are separated from Am and / or Cm, or even U, Np, Pu and Am / Cm are separated from each other, with good separation effect.

[0060] In addition, the recovery rate of each element in the respective eluent can reach a very high level (for example, all higher than 95%). Moreover, the salt content in the obtained various eluents is very low, and after concentration, transformation and sample preparation, they can be analyzed by spectroscopic measurement, radioactivity measurement (including liquid scintillation method, alpha spectrometry, gamma spectrometry, etc.) or mass spectrometry; in some cases, the eluent can even be directly prepared into samples by liquid scintillation method and / or alpha spectrometry and / or gamma spectrometry without concentration and transformation.

[0061] Furthermore, since the series column is used as the separation device, the whole column separation process can be operated continuously, is very simple, easy to realize automation, and has a wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 is a flow diagram of simultaneous separation of U, Np, Pu and element X in the present application.

[0063] Figure 2 is a separation effect diagram of Example 1 provided in the present application. DETAILED DESCRIPTION

[0064] Various exemplary embodiments, features, and aspects of the present application will be described in detail below. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0065] In addition, in order to better illustrate the present application, numerous specific details are given in the following detailed description. Those skilled in the art will understand that the present application can be practiced without certain specific details, which are provided for the purpose of illustration and explanation. In other instances, methods, apparatuses, articles of manufacture, and steps are not described in detail or are presented in a method, apparatus, article of manufacture, or step summary in order to avoid obscuring the subject matter.

[0066] Unless otherwise defined, all terms used in the present specification, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an overly literal or overly formal sense.

[0067] In the present specification, the meaning indicated by "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

[0068] In the present specification, "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", and the like refer to the specific elements (for example, features, structures, properties, and / or characteristics) described in relation to the embodiments and are included in at least one of the embodiments described herein, and can or can not be present in other embodiments. In addition, it should be understood that the elements can be combined in various embodiments in any suitable manner.

[0069] In the present specification, the numerical range indicated by "numerical value A to numerical value B" refers to a range including the end point values A and B. In the present specification, the numerical range indicated by "and above" and "and below" refers to a range including the end point values. In the present specification, the numerical range indicated by "greater than" and "less than" refers to a range not including the end point values.

[0070] In the present specification, "optional" or "optionally" means that the subsequently described event or circumstance can or can not occur, and that the description includes the situation in which the event occurs and the situation in which the event does not occur.

[0071] <Method for solid phase extraction separation>

[0072] The method for solid phase extraction separation of the present application is used to separate each of the actinide elements, which are U, Np and / or Pu, and element X, which is at least one selected from Am or Cm.

[0073] In some preferred embodiments, it is preferable to be adapted to separate each of at least two selected from U, Np or Pu, and element X, or even to separate each of U, Np, Pu and element X.

[0074] In the present application, "separating each of U, Np and / or Pu, and at least one element X selected from Am or Cm" means that, in the presence of at least one of U, Np and / or Pu, and element X in a test solution, each of the above-mentioned actinide elements present in the test solution can be separated.

[0075] In the present application, the method for solid phase extraction separation is implemented by using a technique of a tandem column solid phase extraction.

[0076] For the convenience of understanding, Figure 1 A flow diagram of one specific embodiment of the method for solid phase extraction separation of the present application is exemplarily shown in FIG.

[0077] In the present application, the method for solid phase extraction separation comprises a step (1) of flowing a test solution through a tandem column.

[0078] Specifically, in step (1), the test solution containing the actinide elements (i.e., U, Np and / or Pu and element X) is passed through a tandem column composed of separation column 1 and separation column 2 connected in series. Moreover, the test solution enters the tandem column from the side of separation column 1 of the tandem column, in other words, the test solution passes through separation columns 1 and 2 in sequence.

[0079] In the present application, the order in which the test solution passes through the separation columns in the tandem column is very critical, and if the order of the separation columns is changed, the purpose of the present application cannot be achieved.

[0080] The flow rate of the test solution is not particularly limited and can be appropriately adjusted according to the actual needs. In some preferred embodiments, in order to make the separation columns more fully adsorb, the flow rate of the test solution is 0.05 to 5 mL / min, more preferably 0.2 to 3 mL / min.

[0081] In the present application, the number of tandem connections of each of separation column 1 and separation column 2 is not particularly limited, and each can be only one or a plurality.

[0082] In the present application, when both Am and Cm are contained in the test solution, Am and Cm are not separated. In addition, for at least one element X selected from Am or Cm, the present application is sometimes labeled as "Am and / or Cm" or "Am / Cm".

[0083] In step (1), the separation column 1 is packed with a resin 1 including a porous base resin 1 and a complexing agent 1 supported on the porous base resin 1. The complexing agent 1 is capable of complexing with U, Np, and Pu. The complexing agent 1 is represented by the following formula (1).

[0084] (1)

[0085] In formula (1), each R1 is independently an alkyl group. Each R1 can be the same or different.

[0086] In some preferred embodiments, each R1 is independently a C4-12 straight chain or branched chain alkyl group, more preferably, each R1 is independently a C6-10 straight chain or branched chain alkyl group.

[0087] As examples of the complexing agent 1, the following can be listed without limitation: tri-pentoxyphosphine, tri-hexyloxyphosphine, tri-heptyloxyphosphine, tri-octyloxyphosphine, tri-nonyloxyphosphine, tri-decyloxyphosphine, tri-undecyloxyphosphine, methyl-di-pentoxyphosphine, ethyl-di-pentoxyphosphine, butyl-di-octyloxyphosphine, and the like. These compounds can be used alone or in a combination of two or more.

[0088] In some particularly preferred embodiments, the complexing agent 1 is tri-octyloxyphosphine (tri-octylphosphine, TOPO) from the viewpoint of further improving the separation effect.

[0089] In step (1), the separation column 2 is packed with a resin 2 including a porous base resin 2 and a complexing agent 2 supported on the porous base resin 2. The complexing agent 2 is capable of complexing with the element X. The complexing agent 2 is represented by the following formula (2).

[0090] (2)

[0091] In formula (2), each R2 is independently an alkyl group. Each R2 can be the same or different.

[0092] In some preferred embodiments, each R2 is independently a C4-20 straight chain or branched chain alkyl group, more preferably, each R2 is independently a C6-12 straight chain or branched chain alkyl group.

[0093] As examples of the complexing agent 2, the following can be listed without limitation: TEHDGA, TODGA, and the like.

[0094] In some particularly preferred embodiments, the complexing agent 2 is at least one selected from the group consisting of TEHDGA and TODGA from the viewpoint of further improving the separation effect.

[0095] In the present application, by including the complexing agent 1 in the separation column 1 and the complexing agent 2 in the separation column 2, the separation effect desired in the present application can be achieved.

[0096] In the present application, the material of the porous base resins 1 and 2 is not particularly limited as long as it does not participate in the reaction during the solid state extraction process (i.e., it is inert to the separation process).

[0097] In some preferred embodiments, the porous base resin 1 and the porous base resin 2 are each independently at least one selected from the group consisting of (meth)acrylate porous resins and styrene porous resins from the viewpoint of reducing the cost, higher recovery rate of the target element, and better separation effect.

[0098] In the present application, the term "(meth)acrylate porous resin" refers to a porous resin formed using a polymer in which a unit based on a (meth)acrylate monomer is used as a main component. The term "styrene porous resin" refers to a porous resin formed using a polymer in which a unit based on a styrene monomer is used as a main component.

[0099] In the present application, the specific structure of the porous base resin is not particularly limited and can be appropriately adjusted according to the actual needs (e.g., composition of the test solution, size of the equipment, flow rate of the test solution, etc.).

[0100] In some specific embodiments, the porous base resins 1 and 2 are each in the form of particles. In this case, the average particle diameter of each of the porous base resins 1 and 2 can be 100 nm to 1 mm, preferably 2 μm to 800 μm, and more preferably 20 μm to 200 μm.

[0101] In other specific embodiments, the pore diameter of each of the porous base resins 1 and 2 can be 2 nm to 0.1 mm, preferably 2 nm to 100 nm, and more preferably 5 nm to 15 nm.

[0102] In addition, the porous base resins 1 and 2 can be the same or different, and are preferably the same.

[0103] In the present application, the loading amount of the complexing agent in the resin 1 or 2 is not particularly limited and can be appropriately adjusted according to the actual needs (e.g., composition of the test solution, size of the equipment, flow rate of the test solution, etc.).

[0104] In some embodiments, the loading amount of the complexing agent 1 in the resin 1 can be 5 to 50 mass% (with respect to the total mass of the resin 1 being 100%) from the viewpoint of balancing the cost and the desired separation effect, and preferably 20 to 40 mass%.

[0105] In other embodiments, the loading amount of the complexing agent 2 in the resin 2 can be 5 to 50 mass% (with respect to the total mass of the resin 2 being 100%) from the viewpoint of balancing the cost and the desired separation effect, and preferably 20 to 40 mass%.

[0106] In the present application, the method for loading the complexing agent to the porous base resin is not particularly limited, and various methods known in the art can be employed.

[0107] In some embodiments, the porous base resin (porous base resin 1 or 2) can be washed, and then mixed with the complexing agent (complexing agent 1 or 2) in a solvent, and then the solvent can be removed (for example, by distillation under reduced pressure) to obtain the resin 1 or 2.

[0108] In addition, the usage form of each separation column is not particularly limited. In some embodiments, the separation column 1 can be obtained by packing the resin 1 in a chromatographic column, and the separation column 2 can be obtained by packing the resin 2 in a chromatographic column.

[0109] In the case of using a chromatographic column, in order to better avoid the nuclide residue and wall hanging, it is preferable that the material of the chromatographic column is stainless steel or a high polymer material.

[0110] In addition, the size of the chromatographic column is not particularly limited, and can be appropriately adjusted according to the application scale and the like. In some embodiments, the length of the chromatographic column can be 2 centimeters to 1 meter, for example, 5 centimeters, 7 centimeters, 9 centimeters, 15 centimeters, 20 centimeters, 25 centimeters, 30 centimeters, 40 centimeters, 45 centimeters, 50 centimeters, 55 centimeters, 60 centimeters, 65 centimeters, 70 centimeters, 75 centimeters, 80 centimeters, 85 centimeters, 90 centimeters. In some cases, it can be 2 to 10 centimeters, in some cases, it can be greater than 10 centimeters and less than 50 centimeters, and in some cases, it can be greater than 50 centimeters and less than 1 meter.

[0111] In some embodiments, the inner diameter of the chromatography column is 1 mm to 5 cm, for example, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 18 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm. In some cases, it can be 1 mm to 15 mm, in some cases, it can be greater than 15 mm and less than 30 mm, in some cases, it can be greater than 30 mm and less than 50 mm.

[0112] In the present application, the source of the test solution containing the actinide elements (i.e., U, Np and / or Pu and element X) is not particularly limited. The test solution can be a raw solution to be treated (solution to be treated) or a treated solution.

[0113] In some preferred embodiments, in order to more fully separate the nuclides (i.e., the various elements to be separated described above), in the test solution, U is in +6 valence, Np is in +6 valence, Pu is in +4 valence, and element X is in +3 valence. In the case where the valence of the nuclides in the solution to be treated satisfies the preferred valence described above, it is possible to more easily achieve (1) almost all of U, Np and / or Pu are adsorbed by separation column 1; and (2) almost all of Am and / or Cm are adsorbed by separation column 2.

[0114] In the case where the valence of the nuclides in the solution to be treated does not satisfy the preferred valence described above, the method for maintaining the valence of the nuclides as the preferred valence described above is not particularly limited. For example, the test solution is obtained by adding nitric acid and ammonium vanadate to the solution to be treated containing the actinide elements (i.e., U, Np and / or Pu and element X) to perform acidity adjustment and oxidation pretreatment.

[0115] In some preferred embodiments, in order to adjust the more appropriate acidity to more fully separate the nuclides, in the test solution, the concentration of nitric acid is preferably 0.5 to 10.0 mol / L, more preferably 3 to 5 mol / L.

[0116] In some preferred embodiments, in the test solution, the concentration of ammonium vanadate is preferably 0.01 to 0.5 mol / L, more preferably 0.05 to 0.2 mol / L.

[0117] The oxidation pretreatment is performed by adding nitric acid and ammonium vanadate to the solution to be treated and stirring for a prescribed time.

[0118] In some preferred embodiments, the oxidation pretreatment time is preferably 5 to 60 min, more preferably 10 to 20 min.

[0119] In addition, various other elements can be contained in the test solution of the present application, which varies depending on the source of the solution to be treated.

[0120] Further, in the present application, a carrier solution not containing U, Np, Pu and element X can be passed through the tandem column after the test solution is passed through the tandem column. By this process, the test solution can be passed through the tandem column more sufficiently. In some specific embodiments, the carrier solution can be a nitric acid solution.

[0121] The concentration of the nitric acid solution as the carrier solution can be 0.5 to 10.0 mol / L, preferably 3 to 5 mol / L. Further, the concentration of the nitric acid solution as the carrier solution is more preferably the same as the concentration of the nitric acid in the test solution.

[0122] The flow rate of the carrier solution is not particularly limited and can be appropriately adjusted according to the actual needs. In some preferred embodiments, in order to make the separation column more fully adsorbed, the flow rate of the carrier solution is 0.05 to 5 mL / min, more preferably 0.2 to 3 mL / min.

[0123] In the present application, the solid phase extraction separation method includes the step (2) of eluting the separation column 1 and the separation column 2 with specific eluents, respectively, and collecting the corresponding eluate.

[0124] Specifically, the step (2) elutes the separation column 1 with the Np eluent, collects the eluate containing Np that flows out, elutes the separation column 1 with the Pu eluent, collects the eluate containing Pu that flows out, and / or elutes the separation column 1 with the U eluent, and collects the eluate containing U that flows out; and elutes the separation column 2 with the element X eluent, and collects the eluate containing element X that flows out.

[0125] The order of adding each eluent is not particularly limited and can be appropriately adjusted according to the actual needs. For example, the elution of the separation column 1 can be performed first, followed by the elution of the separation column 2, or the elution of the separation column 2 can be performed first, followed by the elution of the separation column 2. In addition, in some particularly preferred embodiments, in the case where Np, Pu and U are present at the same time, the Np eluent, the Pu eluent and the U eluent are preferably sequentially eluted to the separation column 1.

[0126] The flow rate of each eluent is not particularly limited and can be appropriately adjusted according to the actual needs. In some preferred embodiments, in order to make the separation column more fully desorbed, the flow rate of each eluent is preferably 0.05 to 5 mL / min, more preferably 0.2 to 3 mL / min.

[0127] In the present application, the use of the specific eluents as described below not only achieves the separation of the target elements, but also has a high recovery rate of the target elements and a low salt content.

[0128] In the present application, the Np eluent is a mixed solution containing acethydroxamic acid (AHA) and nitric acid. Preferably, an AHA-nitric acid aqueous solution is used (i.e., an aqueous solution using AHA and nitric acid as solutes).

[0129] The structural formula of acethydroxamic acid (AHA) is shown in formula (3).

[0130] (3)

[0131] In some preferred embodiments, in the mixed solution containing AHA and nitric acid, the concentration of AHA is preferably 0.05-1 mol / L, more preferably 0.2-0.8 mol / L.

[0132] In some preferred embodiments, in the mixed solution containing AHA and nitric acid, the concentration of nitric acid is preferably 0.1-4 mol / L, more preferably 0.2-2 mol / L.

[0133] In the present application, the Pu eluent is a mixed solution containing oxalic acid and ascorbic acid. Preferably, an oxalic acid-ascorbic acid aqueous solution is used (i.e., an aqueous solution using oxalic acid and ascorbic acid as solutes).

[0134] In some preferred embodiments, in the mixed solution containing oxalic acid and ascorbic acid, the concentration of oxalic acid is 0.05-1.0 mol / L, more preferably 0.3-0.8 mol / L.

[0135] In some preferred embodiments, in the mixed solution containing oxalic acid and ascorbic acid, the concentration of ascorbic acid is 0.02-0.8 mol / L, more preferably 0.05-0.4 mol / L.

[0136] In the present application, the U eluent is a solution containing ammonium carbonate. Preferably, an ammonium carbonate aqueous solution is used.

[0137] In some preferred embodiments, in the solution containing ammonium carbonate, the concentration of ammonium carbonate is 0.05-1.5 mol / L, more preferably 0.2-0.8 mol / L.

[0138] In the present application, the element X eluent is a mixed solution containing acethydroxamic acid (AHA) and hydrochloric acid (HCl). Preferably, an AHA-hydrochloric acid aqueous solution is used (i.e., an aqueous solution using AHA and HCl as solutes).

[0139] In some preferred embodiments, in the mixed solution containing AHA and HCl, the concentration of AHA is 0.01-1 mol / L, more preferably 0.05-0.5 mol / L.

[0140] In some preferred embodiments, the concentration of hydrochloric acid (HCl) in the mixed solution containing the AHA and the HCl is 0.01 to 0.5 mol / L.

[0141] In the present application, each of the eluents contains other components in addition to the above-mentioned solutes, such as NaCl, and other unavoidable impurity components.

[0142] In the present application, the recovery rate of each element from the test solution by the solid phase extraction method can reach a very high level. For example, it can be 95% or more.

[0143] In the radiochemical separation, the recovery rate refers to the ratio of the mass (or the activity of the nuclide) of the target element recovered after the separation to the mass (or the activity of the nuclide) of the target element in the original sample before the separation, which is usually expressed in percentage.

[0144] In addition, the solid phase extraction separation method of the present application can further include other steps. For example, a step of concentrating or diluting each eluent, a step of extracting the corresponding element from each eluent, etc.

[0145] These other steps can be performed by methods known in the art.

[0146] <Kit for solid phase extraction>

[0147] The kit for solid phase extraction of the present application is used to separate each of the actinide elements, which are U, Np and / or Pu, and the element X, which is at least one selected from Am or Cm.

[0148] In some preferred embodiments, the kit for solid phase extraction of the present application is preferably adapted to separate each of at least two selected from U, Np or Pu, and the element X, or even to separate each of U, Np, Pu and the element X.

[0149] The kit for solid phase extraction of the present application includes a cascade column composed of a separation column 1 and a separation column 2 connected in sequence, and an eluent for eluting the cascade column. The cascade column has an inlet for injecting a test solution on the side of the separation column 1. It can be understood that the cascade column has an outlet for flowing out the test solution on the side of the separation column 2.

[0150] The eluent is an Np eluent for eluting the separation column 1, a Pu eluent for eluting the separation column 1, and / or a U eluent for eluting the separation column 1, and an element X eluent for eluting the separation column 2.

[0151] In the present application, according to the types of actinide elements contained in the test solution to be treated, the eluent can be at least one selected from an Np eluent, a Pu eluent and a U eluent, and an element X eluent.

[0152] The separation column 1 is packed with resin 1, which includes a porous base resin 1 and a complexing agent 1 loaded on the porous base resin 1.

[0153] The complexing agent 1 is represented by the following formula (1).

[0154] (1)

[0155] In formula (1), R1 is independently an alkyl group.

[0156] The separation column 2 is packed with resin 2, which includes a porous base resin 2 and a complexing agent 2 loaded on the porous base resin 2.

[0157] The complexing agent 2 is represented by the following formula (2).

[0158] (2)

[0159] In formula (2), R2 is independently an alkyl group.

[0160] The Np eluent is a mixed solution containing acethydroxamic acid (AHA) and nitric acid; the Pu eluent is a mixed solution containing oxalic acid and ascorbic acid; the U eluent is a solution containing ammonium carbonate; and the element X eluent is a mixed solution containing acethydroxamic acid (AHA) and hydrochloric acid.

[0161] In other words, the kit of the present application includes the combination of the above-mentioned cascade column and the above-mentioned eluents.

[0162] In addition, the kit of the present application can optionally further include other components, such as a carrier agent, etc.

[0163] In the present application, the details of the separation columns 1 and 2, the resins 1 and 2, the porous base resins 1 and 2, the complexing agents 1 and 2, the eluents, and the carrier agent are each as described above in the section <Solid-phase extraction separation method>.

[0164] Examples

[0165] The embodiments of the present application will be described in detail below with reference to Examples, but those skilled in the art will appreciate that the following Examples are for illustrative purposes only and should not be construed as limiting the scope of the present application. In the Examples, the specific conditions not mentioned are performed under conventional conditions or under the conditions recommended by the manufacturer. In the Examples, the reagents or instruments not mentioned by the manufacturer are all conventional products that can be commercially available.

[0166] <Example 1: Separation of actinides from simulated environmental feed solution>

[0167] (I) Preparation of test solution, carrier agent, and eluents

[0168] (1) Preparation of the test solution: Take an appropriate amount of 233 U, 237 Np, 238-241 Pu and 241 Am tracer into 50 mL test tube A. Weigh a certain amount of solid ammonium metavanadate (the amount is such that its final concentration in the test solution is 0.05 mol / L) into 50 mL test tube B, and add 20 mL of simulated environment solution to test tube B and stir to dissolve.

[0169] The detailed composition of the simulated environment solution is as follows. The medium is 4 mol / L nitric acid, and the metal element composition is (unit: mg / L): Al, 4200; Ca, 4000; Fe, 7000; K, 2000; Mn, 80; Na, 1000; Ni, 200; Pb, 700; Ti, 300.

[0170] Transfer all the solution in test tube B to test tube A, stir and oxidize for 10 min, and the obtained solution is referred to as the test solution.

[0171] (2) The carrier is 4 mol / L nitric acid solution.

[0172] (3) The Np eluent is AHA-nitric acid aqueous solution, specifically 0.5 mol / L AHA + 1.5 mol / L nitric acid. The Pu eluent is oxalic acid-ascorbic acid aqueous solution, specifically 0.6 mol / L oxalic acid + 0.1 mol / L ascorbic acid. The U eluent is 0.5 mol / L ammonium carbonate aqueous solution. The element X (i.e. Am) eluent is AHA-hydrochloric acid aqueous solution, specifically 0.02 mol / L AHA + 0.1 mol / L hydrochloric acid.

[0173] (II) Separation process

[0174] Start the separation process, the flow rate is 0.5 mL / min, and the test solution flows through separation column 1 (loaded with TOPO-loaded resin 1) and separation column 2 (loaded with TEHDGA-loaded resin 2) in turn. After waiting for the test solution in the test solution bottle to enter the separation column, switch to the carrier, and the amount of carrier used is 20 mL.

[0175] (III) Elution process

[0176] After the carrier is finished, start the elution process, and collect each eluent in a test tube, change a test tube every 4 min, and collect 2 mL of eluent in each test tube. Specifically, use 20 mL of Np eluent, 20 mL of Pu eluent, 20 mL of U eluent to elute separation column 1 in turn, and use 20 mL of element X eluent to elute separation column 2. All eluents are collected in 40 test tubes in turn.

[0177] (IV) Analysis after separation

[0178] After the end of the separation process, U eluate, Np eluate, Pu eluate and element X eluate were taken respectively for measurement by liquid scintillation counter and alpha spectrometer. The U eluate was used for U analysis; the Np eluate was used for Np analysis; the Pu eluate was used for Pu analysis; and the element X eluate was used for Am analysis.

[0179] The analysis results of the eluate in the above 40 test tubes are shown in Table 1. Figure 2 According to material balance, the recovery rates of U, Np, Pu and Am in their respective eluate were all higher than 95%. Combined with the alpha spectrum analysis results, it can be seen that the cross contamination of target elements in the eluate was small.

[0180] <Example 2 Separation of actinides from simulated environmental feed solution>

[0181] (One) to (Three) were carried out in the same way as in Example 1, except that the TEHDGA-loaded resin 2 in the separation column 2 was replaced by TODGA-loaded resin 2.

[0182] (Four) Analysis after separation

[0183] After the end of the separation process, U eluate, Np eluate, Pu eluate and element X eluate were taken respectively for measurement by liquid scintillation counter and alpha spectrometer. The U eluate was used for U analysis; the Np eluate was used for Np analysis; the Pu eluate was used for Pu analysis; and the element X eluate was used for Am analysis.

[0184] Similar to the results in Example 1, the recovery rates of U, Np, Pu and Am in their respective eluate were all higher than 95%, and the cross contamination of target elements in the eluate was small.

[0185] <Example 3 Separation of actinides from simulated high-level liquid waste>

[0186] (One) to (Three) were carried out in the same way as in Example 1, except that the simulated environmental feed solution in Example 1 was replaced by simulated high-level liquid waste. The detailed composition of the simulated high-level liquid waste is as follows. The medium is 4 mol / L nitric acid, and the metal element composition (unit: mg / L) is as follows: Na, 18300; Fe, 6000; Al, 5700; Ni, 2900; and Nd, 1500.

[0187] (Four) Analysis after separation

[0188] After the end of the separation process, U eluate, Np eluate, Pu eluate and element X eluate were taken respectively for measurement by liquid scintillation counter and alpha spectrometer. The U eluate was used for U analysis; the Np eluate was used for Np analysis; the Pu eluate was used for Pu analysis; and the element X eluate was used for Am analysis.

[0189] Similar to the results in Example 1, the recovery rates of U, Np, Pu, Am, and the like in the respective eluate were all higher than 95%, and the cross-contamination of the target elements in the respective eluate was small.

[0190] <Example 4 Separation of Actinides in Simulated High-Level Liquid Waste>

[0191] (1) to (3) were carried out in the same manner as in Example 3, except that the TEHDGA-loaded resin 2 in the separation column 2 was replaced with a TODGA-loaded resin 2.

[0192] (Four) Analysis after Separation

[0193] After the end of the separation process of the cascade column, the U eluate, the Np eluate, the Pu eluate, and the element X eluate were respectively taken and measured with a liquid scintillation counter and an alpha spectrometer. Among them, the U eluate was used for the analysis of U; the Np eluate was used for the analysis of Np; the Pu eluate was used for the analysis of Pu; and the element X eluate was used for the analysis of Am.

[0194] Similar to the results in Example 1, the recovery rates of U, Np, Pu, Am, and the like in the respective eluate were all higher than 95%, and the cross-contamination of the target elements in the respective eluate was small.

[0195] <Example 5 Separation of Actinides in Pure Nitric Acid Medium>

[0196] (1) to (3) were carried out in the same manner as in Example 1, except that the simulated environment feed solution in Example 1 was replaced with a 4 mol / L aqueous nitric acid solution.

[0197] (Four) Analysis after Separation

[0198] After the end of the separation process of the cascade column, the U eluate, the Np eluate, the Pu eluate, and the element X eluate were respectively taken and measured with a liquid scintillation counter and an alpha spectrometer. Among them, the U eluate was used for the analysis of U; the Np eluate was used for the analysis of Np; the Pu eluate was used for the analysis of Pu; and the element X eluate was used for the analysis of Am.

[0199] Similar to the results in Example 1, the recovery rates of U, Np, Pu, Am, and the like in the respective eluate were all higher than 95%, and the cross-contamination of the target elements in the respective eluate was small.

[0200] <Example 6 Separation of Actinides in Pure Nitric Acid Medium>

[0201] (1) to (3) were carried out in the same manner as in Example 5, except that the TEHDGA-loaded resin 2 in the separation column 2 was replaced with a TODGA-loaded resin 2.

[0202] (Four) Analysis after Separation

[0203] After the end of the cascade column separation process, U eluate, Np eluate, Pu eluate and element X eluate are taken respectively for measurement by liquid scintillation instrument and alpha spectrometer. The U eluate is used for U analysis; the Np eluate is used for Np analysis; the Pu eluate is used for Pu analysis; and the element X eluate is used for Am analysis.

[0204] Similar to the results in Example 1, the recovery rates of U, Np, Pu and Am in their respective eluates are all higher than 95%, and the cross-contamination of target elements in the eluates is small.

[0205] <Comparative Example 1>

[0206] Except that the TOPO-loaded resin 1 in the separation column 1 is replaced by TEVA-loaded resin 1, (1) to (3) are implemented in the same way as in Example 1.

[0207] (Four) Analysis after separation

[0208] After the end of the cascade column separation process, U eluate, Np eluate, Pu eluate and element X eluate are taken respectively for measurement by liquid scintillation instrument and alpha spectrometer. However, more than 80% of U and Np enter the element X eluate, i.e. the cross-contamination of target elements in the eluates is great.

[0209] <Comparative Example 2>

[0210] Except that the Np eluent is replaced by 0.6 mol / L oxalic acid + 0.1 mol / L ascorbic acid, and the Pu eluent is replaced by 0.5 mol / L AHA + 1.5 mol / L nitric acid, (1) to (3) are implemented in the same way as in Example 1.

[0211] (Four) Analysis after separation

[0212] After the end of the cascade column separation process, U eluate, Np eluate, Pu eluate and element X eluate are taken respectively for measurement by liquid scintillation instrument and alpha spectrometer. However, more than 95% of Np and Pu enter the Np eluate, i.e. the cross-contamination of target elements in the eluates is great.

[0213] It should be noted that although the technical solutions of the present application are introduced by specific examples, those skilled in the art can understand that the present application should not be limited thereto.

[0214] Having described various embodiments of the application, it is to be understood that the above description is meant not to limit and not to encompass all of the possible embodiments covered by the claims. Many modifications and variations of this application can be apparent to those of ordinary skill in the art without departing from the spirit and scope of the described embodiments. It is intended that the scope of the application should only be limited by the appended claims.

Claims

1. A solid phase extraction separation process for separating actinides from each other, the actinides being U, Np and / or Pu and an element X, the element X being at least one selected from Am or Cm, characterized in that, The method comprises: (1) passing a test solution containing the actinide through a cascade column composed of separation column 1 and separation column 2 connected in series, and the test solution entering the cascade column from the side of separation column 1 of the cascade column, the separation column 1 is packed with resin 1, the resin 1 comprising a porous base resin 1 and a complexing agent 1 loaded on the porous base resin 1, the complexing agent 1 is represented by the following formula (1): (1) in formula (1), R1 is independently alkyl; the separation column 2 is packed with resin 2, the resin 2 comprising a porous base resin 2 and a complexing agent 2 loaded on the porous base resin 2, the complexing agent 2 is represented by the following formula (2): (2) in formula (2), R2 is independently alkyl; (2) eluting the separation column 1 with Np eluent, collecting the effluent containing Np, eluting the separation column 1 with Pu eluent, collecting the effluent containing Pu, and / or eluting the separation column 1 with U eluent, collecting the effluent containing U; and eluting the separation column 2 with element X eluent, collecting the effluent containing element X; the Np eluent is a mixed solution containing acethydroxamic acid (AHA) and nitric acid; the Pu eluent is a mixed solution containing oxalic acid and ascorbic acid; the U eluent is a solution containing ammonium carbonate; the element X eluent is a mixed solution containing acethydroxamic acid (AHA) and hydrochloric acid.

2. The solid phase extraction separation method of claim 1, wherein, In the test solution, U is +6 valence, Np is +6 valence, Pu is +4 valence, and element X is +3 valence.

3. The solid phase extraction separation method of claim 2, wherein, The test solution is obtained by adding nitric acid and ammonium vanadate to a to-be-treated solution containing the actinide for acidity adjustment and oxidation pretreatment.

4. The solid phase extraction separation method of claim 1, wherein, in formula (1), R1 is independently C4-12 linear or branched alkyl; and / or in formula (2), R2 is independently C4-20 linear or branched alkyl.

5. The solid phase extraction separation method of claim 1, wherein, The porous base resin 1 and the porous base resin 2 are each independently at least one selected from (meth)acrylate porous resin and styrene porous resin; and / or the loading amount of complexing agent 1 in the resin 1 is 5-50% by mass; and / or the loading amount of complexing agent 2 in the resin 2 is 5-50% by mass.

6. The solid phase extraction separation method of claim 1, wherein, The separation column 1 is obtained by packing the resin 1 in a chromatographic column, and / or The separation column 2 is obtained by packing the resin 2 in a chromatographic column.

7. The solid phase extraction separation method of claim 1, wherein, in the mixed solution containing acethydroxamic acid (AHA) and nitric acid, the concentration of acethydroxamic acid (AHA) is 0.05-1 mol / L, and the concentration of nitric acid is 0.1-4 mol / L; and / or in the mixed solution containing oxalic acid and ascorbic acid, the concentration of oxalic acid is 0.05-1.0 mol / L, and the concentration of ascorbic acid is 0.02-0.8 mol / L; and / or in the solution containing ammonium carbonate, the concentration of ammonium carbonate is 0.05-1.5 mol / L; and / or in the mixed solution containing acethydroxamic acid (AHA) and hydrochloric acid, the concentration of acethydroxamic acid (AHA) is 0.01-1 mol / L, and the concentration of hydrochloric acid is 0.01-0.5 mol / L.

8. The solid phase extraction separation method of claim 1, wherein, The flow rate of each of the test solution and the eluents is 0.05 to 5 mL / min.

9. The solid phase extraction separation method of claim 1, wherein, In step (1), after passing the test solution through the cascade column, a carrier solution not containing U, Np, Pu and element X is passed through the cascade column.

10. A kit of parts for solid phase extraction of actinides, U, Np and / or Pu, each separately, with an element X, the element X being at least one selected from Am or Cm, characterized in that, The kit includes: a cascade column composed of separation column 1 and separation column 2 connected in series, and eluents for eluting the cascade column, The cascade column has an inlet for injecting a test solution on the side of the separation column 1, The eluents are an Np eluent for eluting separation column 1, a Pu eluent for eluting separation column 1, and / or a U eluent for eluting separation column 1, and an element X eluent for eluting separation column 2; The separation column 1 is packed with resin 1 including a porous base resin 1 and a complexing agent 1 supported on the porous base resin 1, The complexing agent 1 is represented by the following formula (1): (1) In formula (1), each R1 is independently an alkyl group; The separation column 2 is packed with resin 2 including a porous base resin 2 and a complexing agent 2 supported on the porous base resin 2, The complexing agent 2 is represented by the following formula (2): (2) In formula (2), each R2 is independently an alkyl group; The Np eluent is a mixed solution containing acethydroxamic acid (AHA) and nitric acid; The Pu eluent is a mixed solution containing oxalic acid and ascorbic acid; The U eluent is a solution containing ammonium carbonate; The element X eluent is a mixed solution containing acethydroxamic acid (AHA) and hydrochloric acid.

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